$ D = \left[\begin{array}{rrr}7 & 1 & 9 \\ 0 & 5 & 6 \\ 0 & 8 & 0\end{array}\right]$ What is $ D^{T}$ ?
Explanation: To find the transpose, swap the rows and columns. $ D^{T}$ = $\left[\begin{array}{rrr}7 & 0 & 0 \\ 1 & 5 & 8 \\ 9 & 6 & 0\end{array}\right]$